Hyperinflation in COPD: which parameter best reflects clinical outcomes Measures?

<bold>Introduction:</bold> Chronic Obstructive Pulmonary Disease (COPD) is a chronic lung disease characterized by persistent airflow limitation that is not fully reversible, and could be associated to hyperinflation. Identifying reliable parameters that correlate with clinical outcomes remains a challenge. <bold>Aims:</bold> To determine which lung volume parameter exhibits superior correlation with dyspnea, exacerbation frequency and quality of life in COPD patients. <bold>Methods:</bold> This was a cross-sectional study including 115 male COPD patients diagnosed with spirometry and classified according to GOLD guidelines (post-bronchodilator FEV1/FVC ratio <70%), who had been referred from January 2021 to December 2022 to Pulmonary Function Testing Department at Abderrahmane Mami Hospital, Ariana. We analyzed lung function (forced expiratory volume in one second (FEV1%), residual volume (RV%), Functional Residual Capacity (FRC%), Total Lung Capacity (TLC%), RV/TLC ratio), dyspnea (mMRC-score) and quality of life assessed using COPD assessment Test (CAT-score). <bold>Results:</bold> The mean age (years old) and the mean smoking intensity (pack-year) were respectively 64.89±7.33 and 51.52±27.35. The mean FEV1% was 50.93±19.94. RV and RV/TLC ratio were positively correlated with mMRC score(p<0.05, r=0.332 and p=0.003,r=0.589), CAT score(p<0.05,r=0.409 and p<0.001, r=0.576) and exacerbation frequency(p<0.05, r=0.449 and p<0.001, r=0.491). For CPT only a positive correlation with exacerbation frequency was found (p=0.032, r=0.242). <bold>Conclusion:</bold> RV/TLC ratio correlates better than RV with clinical outcomes. Thus, adapting therapeutic interventions to hyperinflation patterns could significantly decrease exacerbation risks and improve patients’ quality of life.